Everyone gets a little bulkier when diving a rebreather, but it is no excuse for poor trim. Bailout bottles can still be carried cleanly, but the technique for carrying them varies from traditional open circuit scuba gear. Depending on whether you carry aluminum or steel tanks or whether you are running a DPV, you may choose to carry both tanks on the left or balance them right and left. Personally, I prefer to balance my bailouts and stages right and left. It keeps my system standardized whether I carry two or four bottles.
If you have over-shoulder counterlungs, the chest d-ring can be difficult to get to. Even if you are able to clip in that location, the bottle may interfere with ADV operation, dump valves, etc. A technique borrowed from side mount diving helps the diver move the bottle into a more streamlined path. It makes the bailout regulator easier to find and offers the diver good trim.
When reviewing the streamlining of many divers, you will notice that stage or bailout bottles often hang perpendicular to the body. As a cave diver, this simply won’t help me get through a small space or protect the cave. Using side mount technique, the bottles move into a position that is in line with the diver in horizontal trim.
The bottom of the bottle can be clipped into a “butt-plate” manufactured by Dive Rite (Nomad) or Golem Gear (Amardillo). Golem Gear also carries a double d-ring that slides on the crotch strap and can be used in a similar fashion. The top end of the tank is slung under a bungee cord instead of clipped. The back of the bungee attaches to the back-plate at about shoulder blade level with a quick link or stopper knot and the front of the bungee is clipped to the chest d-ring. The clips on the stage bottle should be installed close to 180 degrees opposite from the tank valve hand-wheel so that the bungee will slide easily over the hand-wheel.
When the bottle is properly hung, it will ride lower than a traditional stage bottle with the valve tucking easily under the armpit of the diver. The tank should run parallel to the diver’s side in good trim. Tanks are quicker to remove and replace. Regulators are easier to access. Swimming trim is improved and the environment is protected from unnecessary damage
I made a short video that describes this technique. It can be viewed by clicking here.